Effect of Clay as Additive Element in Recycling Waste Porcelain and Sintering Temperature

Abstract

Porcelain tile production has been consistently growing worldwide at an approximate rate of 300 million m²/year. This implies that there is an increasing demand for porcelain raw materials. The industry's commercial success was due to the constant and continuous increase in both technical and aesthetic performance. Due to the complex nature of its raw materials, vigorous firing process and processing approach, porcelain represent the most intricate ceramic system. This paper studied effect of sintering temperature using recycled porcelain and clay as additive in the production of porcelain on physical and mechanical properties of the new product. Waste porcelain was treated with HCl acid, dried in an oven to remove the moisture content and sieve with 50µm aperture. Clay was added to the treated porcelain powder at 0%, 2%, 4%, 6%, 8% and 10% mixed with a ball mill machine, dry pressed into pallet at 91 MP and sintered at 1100 °C, 1150 °C and 1200 °C for 2 hours soaking time. Physical and mechanical properties such as volume shrinkage, mass loss, bulk density, water absorption and compressive strength as well as microstructural analysis were determined. At a sintering temperature of 1200 °C and clay composition of 2%, the maximum value of compressive strength was 863.15 MPa, indicating the overall maximum. Furthermore, at this composition, the value of the mass loss, shrinkage, bulk density and water absorption of porcelain waste with clay addition was 5.93%, 64%, 2.53% and 6.09%, respectively.